FIG. 1 is a block diagram of a common RF front end device. The RF (radio frequency) front end device 10 is used to transmit or receive an RF signal, and comprises an antenna unit 11, a first switch unit 131, a second switch 133, a receiving unit 151 and a transmitting unit 153. The receiving unit 151 and transmitting unit 153 are connected to the antenna unit 11 via the first switch unit 131 and the second switch unit 133 respectively.
The first switch unit 131 may be turned on, and the second switch unit 133 may be turned off. Thus, the antenna unit 11 is able to be connected to the receiving unit 151 via the first switch unit 131, and the RF signal received by the antenna unit 11 is able to be transmitted to the receiving unit 151.
Otherwise, the first switch unit 131 may be turned off, and the second switch unit 133 may be turned on. Thus, the antenna unit 11 is able to be connected to the transmitting unit 153 via the second switch unit 133, and the transmitting unit 153 is able to transmit the RF signal to the antenna unit 11.